Various compositions comprising a plurality of thermoplastic resins have hitherto been proposed. Many recent inventions directed to compositions mainly for industrial parts are to realize the quality balance which has not been obtained by a single resin, by combining the excellent resistance to chemicals and molding processability that a crystalline polymer has and the excellent thermal characteristics and dimensional stability that an amorphous polymer has. For example, Japanese Patent Publication No. 7069/67 discloses a combination of a polypropylene (hereinafter referred to as "PP", for brevity) and a polyphenylene ether (hereinafter referred to as "PPE", for brevity), Japanese Patent Publication No. 41663/84 discloses a combination of a polyamide (hereinafter referred to as "PA", for brevity) and PPE, and Japanese Patent Publication No. 21664/76 discloses a combination of a polyester (hereinafter referred to as "PES", for brevity) and PPE.
However, those crystalline polymer and amorphous polymer are inherently immiscible with each other and are reluctant to be mixed with each other, whereby the mechanical strength of the composition formed by mixing the polymers does not reach a practically required performance.
Accordingly, various attempts have been proposed to improve the qualities by adding compatibilizers or rubber components for facilitating mixing of polymer components which are reluctant to be mixed with each other. For example, for the combination of PPE and PP, the addition of SBS (styrene-butadiene block copolymer) or its hydrogenated rubber is disclosed in Japanese Patent Application (OPI) Nos. 103557/83 and 76547/85 (the term "OPI" as used herein means an "unexamined published application"), for the combination of PES and PPE, the addition of a specific compatibilizer for phenoxy resin is disclosed in Japanese Patent Application (OPI) No. 147465/85, and for the combination of PA and PPE, the addition of a rubber such as SBS, etc., is disclosed in Japanese Patent Application Nos. 220737/85 and 265358/85.
However, those attempts have not yet satisfied the wider and higher performance required in recent industrial fields.